1. Field of the Invention
The present invention relates to surgical instruments for securing sutures in tissue and, more particularly, is directed to instruments for forming a plurality of suture throws at a location remote from a surgical site, running the throws serially down the lengths of suture so as to form a knot at the surgical site, and cutting the suture ends adjacent the knot.
2. Description of the Prior Art
In both closed (e.g. arthroscopic) and open surgeries, it is frequently necessary to form a knot at a surgical site using two lengths of suture emanating from the surgical site, wherein the two lengths of suture must be manipulated with respect to one another at a location remote from the surgical site.
With one known procedure, a "taut-line hitch" knot is formed in the loose ends of the suture at a location remote from the surgical site from which the suture ends emanate, and then the knot is run down the suture ends to the surgical site by pulling with a sawing motion on the appropriate suture ends. A significant drawback to this procedure is that as the appropriate suture end is pulled through the tissue in which the suture is implanted so as to run the knot down to the surgical site, the sawing motion imparted to the suture ends causes the latter to tend to cut and abrade the tissue.
An alternative procedure consists of forming a throw in the suture at a location remote from the surgical site from which the suture ends emanate, running the throw down the length of suture to the surgical site, forming a second throw in the suture at a location remote from the surgical site, running that throw down the length of suture to the surgical site so that it sits atop the first throw, and thereafter repeating the foregoing process as many times as necessary so as to form the desired knot at the surgical site. As used herein, a "turn" consists of two ends of suture which are looped over one another one or more times, a "throw" consists of one or more turns, and a "knot" consists of two or more throws laid on top of one another and tightened so as to lock the two strands of suture relative to one another. Once the knot has been made, the free suture ends are cut near the knot by means of surgical scissors or the like.
In cases of open surgical procedures, such as abdominal surgery, the trimming of free suture ends in this manner (or with a knife) presents little problem. In the case of so-called closed surgical procedures, such as arthroscopic procedures, however, the trimming of free suture ends is more problematic. Conventional scissors or knife blades are unable to reach the surgical site because of the small nature of the incisions involved. Consequently, the use of such trimming mechanisms is inappropriate. Long free suture ends after trimming are almost always undesirable, and may be damaging in closed and/or microscopic surgical cases. Miniaturized surgical scissors and knives exist which may extend through small incisions to a closed surgical site, but the insertion, removal and positioning of these devices are sometimes difficult, and are not without risk. For example, it will be understood that once the suture knot is set, the trimming operation requires the removal of the rundown tool and the subsequent insertion of the cutting tool. This sequence not only adds steps to an already delicate procedure, but also introduces risks of tool and tissue damage. Specifically, the tool may damage the walls of the incision or itself be nicked or dulled during insertion through a cannula to the surgical site. Also, once present at the surgical site, the tool must be manipulated to contact and sever the free suture ends. The latter manipulation is inherently dangerous, and may adversely impact upon the success of the entire surgical procedure. Additionally, the presence of unguarded knife edges in the operating theater always presents risk to operating room personnel as well as patients. The provision of guarding mechanisms for cutting edges accordingly is desirable where such is possible without adverse impact upon the surgical procedure or technique involved.
Arthrex Arthroscopy Instruments, Inc. of Black Rock, Conn. manufactures several tools for running a suture throw down suture ends to a surgical site from a location remote from the surgical site. One such tool is identified as the Arthrex Arthroscopy Knot Pusher (Model No. AR-1310). This knot pusher comprises an elongate shaft having an end portion which is inclined slightly with respect to the long axis of the shaft. The end portion includes a bore extending therethrough. After a throw is formed in the suture ends at a location remote from the surgical site from which the suture ends emanate, one of the ends is threaded through the bore in the end portion of the knot pusher. Then the tool is run down the length of that suture end, while maintaining appropriate tension on the suture ends, so as to push the throw toward the surgical site. Once the first throw has been run down the suture lengths to the surgical site, another throw may be formed in the suture ends at a location remote from the surgical site and then run down the suture ends to the surgical site so that it sits atop the first throw. This procedure may be repeated as many times as desired so as to form a knot at the surgical site.
Arthrex Arthroscopy Instruments, Inc. manufactures another knot pusher tool identified as Model No. AR-1311. This tool comprises an elongate shaft having a rounded front end, and a pair of holes extending in from the sides of the shaft at an angle and terminating at the front end of the shaft. To use the Model No. AR-1311 tool, a throw is formed in the suture ends emanating from the surgical site. Then, each of the free ends of the suture extending away from the throw is threaded into a corresponding respective one of the holes in the front end of the tool and caused to pass out the end of that hole intersecting the side of the tool. Next, the surgeon grasps the suture ends extending out of the holes in the sides of the tool and applies tension to the suture ends. Thereafter, while maintaining this tensioning of the suture ends, the surgeon urges the tool toward the surgical site by pushing against the rear end of the tool, typically with his or her stomach, thereby causing the tool to run the throw down the suture ends to the surgical site. As the throw is run down to the surgical site, successive portions of the suture ends emanating from the surgical site pass through the holes in the rundown tool. Finally, the rundown tool is extracted from the surgical site, whereby the suture ends pass back through, and ultimately are removed from the holes in the rundown tool. Subsequent throws are run down to the surgical site following this procedure.
Yet another Arthrex rundown tool is illustrated, although not described, on page 7 of a brochure published by Arthrex Arthroscopy Instruments, Inc. entitled "The Arthrex Grasping Stitcher System". This rundown tool comprises an elongate shaft which apparently has a rounded or convex V-shaped front end, and a pair of axially-extending, diametrically opposed grooves which terminate at the front end of the tool. A ring surrounds and engages the front end of the shaft, whereby the grooves are surrounded by the ring. This Arthrex tool apparently functions substantially identically to the Arthrex tool Model No. AR-1310 described above, except that each of the suture ends is positioned in a respective one of the elongate grooves and is passed underneath the surrounding ring, rather than being threaded in the holes at the front end of the Arthrex tool Model No. AR-1310.
The operation of all three of the above-mentioned rundown tools of the Arthrex Arthroscopy Instruments, Inc., contemplates that the free ends of the suture after the knot is set are to be trimmed in one of the well known manners discussed above.